1. Field of the Invention
The present invention relates to extraction of power from a solar cell, and an apparatus and method for obtaining maximum power from the solar cell. More specifically, the present invention relates to an apparatus and method capable of extracting maximum power from a solar cell using a simple circuit by effectively extracting power without a complex circuit or component.
2. Discussion of Related Art
Solar energy is an energy source that is not artificially produced energy but can be obtained from nature. Among non-polluting energy sources, solar energy is the most noticeable as a next-generation energy source, and related technology is being actively developed. A solar cell capable of obtaining solar energy is a device for receiving energy from the sun and producing power. An amount of the produced power varies with an angle or amount of solar light and a temperature of the solar light.
Unlike a typical cell, a solar cell exhibits a nonlinear current-voltage curve. Accordingly, it is necessary to find a maximum power point and extract power in order to derive maximum power.
There are several conventional techniques for extracting maximum power. In a first method, a property of a solar cell is recognized in advance to find a relationship between voltage and current, and voltage and current for maximum power are induced from a measured voltage and current, based on the relationship. This first method has a problem in that the property must be recognized in advance and stored in the form of a look-up table. In a second method, a change of voltage and current, and therefore also power, is detected to obtain higher power using an operation unit. This second method has high accuracy, but requires additional components, such as the operation unit capable of performing various operations including multiplication.
Such methods require a number of additional components, such as an operation unit and a storage device.